Marilena Koppa, a member of the European Parliament's Progressive Alliance of Socialists and Democrats, formally announced on Tuesday that she is leaving the ranks of PASOK, the junior partner in Greece's two-party coalition government.

In an announcement, Koppa said that she will remain an independent member of the Progressive Alliance of Socialists and Democrats, of which she is the representative on issues of defense and security.

Koppa suggested that her decision was prompted by a difference of opinion with the socialist party's leadership.

Earlier reports suggested that Koppa is considering joining Democratic Left ahead of twin elections in May for European Parliament and local authorities.